Petroleum distillate fuels gelled with copolymers of ethylene



United States Patent 3,542,531 PETROLEUM DISTILLATE FUELS GELLED WITHCOPOLYMERS 0F ETHYLENE Gordon D. Hiatt and Oliver W. Kaul, Rochester,N.Y.,

assignors to Eastman Kodak Company, Rochester, N.Y.,

a corporation of New Jersey No Drawing. Filed May 1, 1968, Ser. No.725,903

Int. Cl. C101 7/02 US. Cl. 44--7 Claims ABSTRACT OF THE DISCLOSURE Thepresent invention provides petroleum distillate fuel compositionscomprising a petroleum distillate fuel having a gelling agent selectedfrom the group consisting of ethylene-ethylacrylate, and ethylene-vinylacetate copolymers dispersed therein, which compositions are gelled atroom temperature and liquid at elevated temperatures of about 55 C. Theinvention further provides a method for producing the above-describedpetroleum distillate fuel compositions; comprising the steps of: (1)dispersing the above-described gelling agents in the petroleumdistillate fuel, (2) warming the resulting mixture at elevatedtemperatures to form a gellable fuel dispersion, and (3) cooling thefuel dispersion.

The present invention relates to gelled petroleum distillate fuel oilsand to a method of producing the same.

In the practical use of fuel oil, it is desirable in some cases forsafety reasons to be able to store it in a solid form. This isparticularly true, for example, in th case of aviation jet fuel which isutilized in both military and civilian aircraft applications. Therupturing of fuel tanks in jet aircraft in crashes during landing andtake-off and the resulting spreading of the highly flammable fuel aroundthe aircraft, into the passenger compartment and over surroundingdwellings and service structures has cost numerous lives which mighthave been saved had the fuel remained solid or gelled and confined andhence, less subject to the spreading of fire. Hence, the development ofa solid or semisolid fuel which does not flow except under certainextraordinary environmental conditions has been and continues to be animportant problem.

It is, therefore, an object of the present invention to provide a fuelcomposition for jet aircraft which is a gel or nonflowing semisolidunder normal storage condi tions, but which is readily convertible to afree-flowing conventional fuel under easily reproducible, but atypicalconditions of elevated temperatures.

According to the present invention, there is provided a petroleumdistillate fuel composition comprising:

(a) from about 75 to about 95 weight percent of a petroleum distillatefuel having a boiling point of from about 250 to about 750 F.; and

(b) from about 5 to about 25 weight percent of a gelling agent selectedfrom the group consisting of:

(l) ethylene-ethylacrylate copolymers consisting essentially of fromabout 15 to about 25 weight percent of ethylacrylate and the remainderbeing ethylene, and

(2) ethylene-vinyl acetate copolymers consisting essentially of fromabout 15 to about 25 weight percent of vinyl acetate with the remainderbeing ethylene.

The invention further provides a method for preparing theabove-described petroleum distillate fuel compositions which methodcomprises the steps of:

(a) dispersing a gelling agent of the typ described above in thepetroleum distillate fuel at a temperature of from about 110 to about150 F., thus forming a petroleum distillate fuel dispersion in liquid orfluid form, and

3,542,531 Patented Nov. 24, 1970 ice (b) subsequently cooling thepetroleum distillate fuel dispersion to a temperature below about 100 F.

The petroleum distillate fuels in which the gelling agents may be usedto produce the gelled compositions which will be described in moredetail below include aviation turbo-jet fuels and kerosen es suitablefor use in jet engines. Such aviation turbo-jet fuels normally boilbetween about 250 and about 550 F. and are used in both military andcivilian aircraft. Kerosenes suitable for treatment in accordance withthi invention will normally have boiling points of between about 300 and750 F. and are generally referred to as No. l and No. 2 fuel oils.

Apparently the particular manner in which the gelling agents of thisinvention are manufactured has no influence on their peculiarly valublegelling properties. All that is necessary, insofar as the successfulpractice of the present invention is concerned, is that the copolymericgelling agents be polymerized to an extent sufiicient to make them solid(i.e., nonliquid) at about 25 C. Thus the copolymeric gelling agents ofthis invention should generally have a melt index of at least about 1.Methods for manufacturing the copolymeric gelling agents of thisinvention are well known in the art and need not be detailed herein.

EXAMPLE Ten thousand parts of JP-4 jet fuel are warmed carefully to atemperature of 140 F. Into this Warm jet fuel are poured slowly and withtirring, one thousand parts of a powdered ethylene/ethyl acrylatecopolymer having a melt index of about 12 and containing 19.5 weightpercent of ethyl acrylate. The resulting mixture is then stirred until asmooth solution is obtained while maintaining a temperature of 140-150F. Upon cooling to ambient room temperature, the mixture is observed togel to such an extent that it cannot be simply poured readily from aninverted open container.

This gelled fuel in an aircraft fuel tank may be heated locally (nearthe fuel outlet of the tank) as the fuel is needed for the engines.Other effective gelling agents such as E/VA copolymers and high meltingparafiins can also be present in the gelled fuel compositions of thisinvention. In a manner similar to that of the foregoing example, any ofthe gelled fuel compositions of this invention can be manufactured.

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit :and scope of theinvention as described hereinabove and as defined in the appendedclaims.

We claim:

1. A gellable petroleum distillate fuel composition comprising:

(a) from about to about 95 weight percent of a petroleum distillate fuelhaving a boiling point of from about 250 to about 750 F.; and

(b) from about 5 to about 25 weight percent of a gelling agent selectedfrom the group consisting of (l) ethylene-ethyl acrylate copolymersconsisting essentially of from about 15 to about 25 weight percent ofethyl acrylate and from about 75 to about weight percent of ethylene;and (2) ethylene-vinylacetate copolymers consisting essentially of fromabout 15 to about 25 weight percent of vinyl acetate and from about 75to about 85 weight percent of ethylene and (3) mixtures thereof.

2. A gellable petroleum distillate fuel composition as in claim 1wherein said gelling agent is an ethylene/ethyl acrylate copolymer.

3. A gellable petroleum distillate fuel composition as in claim 1,wherein said gelling agent is an ethylene/vinyl acetate copolymer.

4. A gellable petroleum distillate fuel composition as in claim 1wherein said fuel is jet fuel boiling within the range of from about 250F. and about 550 F.

5. A method for producing a gelled petroleum distillate fuel comprisingthe steps of (a) dispersing from about 5 to about 25 weight percent of agelling agent selected from the group consisting of 1)ethylene-ethylacrylate copolymers' sentially of from about to aboutWeight percent of vinyl acetate and from about to about weight percentof ethylene, in a petroleum distillate fuel having a boiling point offrom about 250 to about 750 F.;

4 (b) warming the resulting dispersion at a temperature of from about toabout F. to form a petroleum distillate fuel dispersion; and (c) coolingsaid petroleum distillate fuel dispersion to a temperature below about100 F.

References Cited UNITED STATES PATENTS 3,084,033 4/ 1963 Kelly et a1.44-7 3,219,619 11/1965 Dickerson 447 3,232,720 7/1966 Kepple 44-73,232,721 2/1966 Coyner et a1. 44--7 BENJAMIN R. PADGETT, PrimaryExaminer US. Cl. X.R. 149109

